Problem with Black Lava Lamp

[Jordan V]

I bought a black lava lamp from spencers today. It is a 52 Oz Lava Brand lamp. It has a silver metallic base and is a product of Haggerty Enterprises. The problem i'm having is my black lava is currently brown. It does not appear to want to turn black anytime soon. I've had it on for about 5 hours now. Was hoping for any suggestions. Any help would be greatly appreciated. Thank you.